microbes from tomato, apricot, apple, seabuckthorn, andPodophyllum hexandrum
(medicinal plant) illustrative of the overwhelmingly viewed genera Bacillus,
Pseudomonas,EnterobacterandSerratiawere tried for their abilities to enhance
establishing of their host plant (Mehta et al. 2014 ; Kumar et al. 2015 ; Sharma et al.
2016 ). After endophytic inoculation and resulting development in soil, we saw that
the root structures of inoculated apple cuttings were frequently denser with
numerousfine attaches contrasted with those of the noninoculated control plants.
Root arrangement was moderate for noninoculated plants. Interestingly, for cuttings
that were permitted to establish in the vicinity of the chose endophytes, root
development was started inside of 1 week, and shoot arrangement was more
declared contrasted with that of the noninoculated plants.
The use of P-solubilizers is rapidly increasing in agriculture and horticulture and
offers afinest way to replace chemical fertilizers and pesticides (Zaidi et al. 2014 ;
Ahemad 2015 ). Earlier, Walia et al. (2013a) had isolated and characterized different
P-solubilizers from the rhizosphere soils/roots of tomato having multiple plant
growth-promoting traits (PGPTs). For the testing of effective P-solubilizers, a pot
culture experiment was conducted where they reported a significant increase in
shoot length, root length and dry matter production of shoot and root of tomato
seedlings. Among seven P-solubilizers, strain CKT1 exhibited concomitant pro-
duction of PGPTs, i.e., siderophore production, indoleacetic acid production,
nitrogenfixation activity, and hydrogen cyanide production. Significant increase
was observed in seed germination (36.08%), shoot length (5.22%), root length
(21.12%), shoot dry weight (63.50%) and root dry weight (54.08%), nitrogen
(18.75%), potassium (57.69%) and phosphorus (22.22%) as compared to uninoc-
ulated control. This study, therefore, suggests that the use of single strain inoculum
of CKT1 with multiple PGPTs offers a new concept to address multiple modes of
action.
In an another study by Mehta et al. ( 2013 ) endophytic P-solubilizing bacterial
isolateBacillus circulansCB7 isolated from apple rhizosphere soil of Himachal
Pradesh, India exhibited PGPTs of auxin, nitrogenase activity, ACC deaminase
activity, siderophore production, and antifungal activity againstDematophora
necatrix. In vivostudies showed remarkable increase in seed germination(22.32%),
shoot length (15.91%), root length (25.10%), shoot dry weight (52.92%) and root
dry weight (31.4%). Also, the nutrient uptake by plants, i.e., nitrogen (18.75%),
potassium (57.69%) and phosphorus (22.22%) was increased in shoot biomass.
These results exhibited strongly that isolate CB7 has the favorable PGPR traits to be
developed as a biofertilizer to boost soil fertility and enhance plant growth.
The synergistic effect of the combination of three PGPRs,Bacillus licheniformis
CECT 5106, Pseudomonas fluorescens CECT 5398, and Chryseobacterium
balustinumCECT 5399 with LS 213 on the growth promotion and biocontrol on
tomato and pepper against Fusariumwilt and Rhizoctonia damping off was
observed by Domenech et al. ( 2006 ). They concluded that when both rhizobac-
terium and strain LS213 were combined together to form an inoculum, the growth
parameters were significantly higher than with individual rhizobacterium, in tomato
and pepper, which revealed a synergistic and most effective effect on growth
4 Endophytic Bacteria: Role in Phosphate Solubilization 83